Hydrogen sulfide utilization

Free-Radical-Initiated Synthesis. Free-radical-initiated reactions of hydrogen sulfide to alkenes are commonly utilized to prepare primary thiols. These reactions, where uv light is used to initiate the formation of hydrosulfuryl (HS) radicals, are utilized to prepare thousands of metric tons of thiols per year. The same reaction can be performed using a radical initiator, but is not as readily controlled as the uv-initiated reaction. These types of reactions are considered to be anti-Markownikoff addition reactions. 

It is interesting to note that Kulstad and Malmsten have utilized yet another method for introducing nitrogen into the crown precursors. They utilize sodium azide in DMSO to displace halogen from triethylene glycol dichloride. The bis-azide is then reduced using hydrogen sulfide in ethanol. ... 

Fresh and frozen human tissue samples obtained from brain, liver, and kidney have been analyzed for hydrogen sulfide levels by sulfide-derived methylene blue determination using ion-interaction reversed-phase HPLC (Mitchell et al. 1993). This method can quantify nmol/g levels of sulfide. Gas dialysis/ion chromatography with ECD has been utilized for measurement of sulfide in brain tissue with 95-100% recovery (Goodwin et al. 1989). 

The Iodometric method has also been utilized in analyzing hydrogen sulfide in the air (EPA 1978). The method is based on the oxidation of hydrogen sulfide by absorption of the gas sample in an impinger containing a standardized solution of iodine and potassium iodide. This solution will also oxidize sulfur dioxide. The Iodometric method is suitable for occupational settings. The accuracy of the method is approximately 0.50 ppm hydrogen sulfide for a 30-L air sample (EPA 1978). 

Reductions in organic chemistry utilizing zinc, iron, and hydrogen sulfide, have been performed since the 1840 s. Catalytic hydrogenation came about in 1897, and reduction with metal hydrides came into usage in 1947. 

Carbon Black Oil Usually a viscous, highly aromatic residual oil utilized in the manufacture of carbon black. These oils may also contain polynuclear aromatic compounds, hydrogen sulfide, and ash. 

Although there are some applications in gas emissions reduction, for example, hydrogen sulfide and ammonia removal by utilizing carboxylic acid resins and ammonium anion-exchange resins, ion exchange is mainly used in wastewater treatment. Some characteristic environmental applications are the following (Noble and Terry, 2004) ... 

Cellular hypoxia may occur in spite of adequate ventilation and oxygen administration when poisoning is due to cyanide, hydrogen sulfide, carbon monoxide, and other poisons that interfere with transport or utilization of oxygen. Such patients may not be cyanotic, but cellular hypoxia is evident by the development of tachycardia, hypotension, severe lactic acidosis, and signs of ischemia on the electrocardiogram. 

Chemical Properties. Thiophosgene is more resistant to hydrolysis than its oxygen analogue, phosgene, but it is slowly hydrolyzed to carbon dioxide, hydrogen sulfide, and hydrochloric acid. It can be oxidized to a lacrimatory thiophosgene 5-oxide (41). Its utility in organic synthesis has been... 

The H2S. sulfanes are the subject of several reviews (129,133). Except for hydrogen sulfide these have no practical utility. Sodium tetrasulfide [12034-39-8] is available commercially as a 40 wt % aqueous solution and is used to dehair hides in tanneries, as an ore flotation agent, in the preparation of sulfur dyes (qv), and for metal sulfide finishes (see Leather Mineral recovery and processing). 

The produced water is a combination of water from a free-water knockout and from heater treaters. An aeration tower is used to oxidize the iron and hydrogen sulfide, and chlorine is also added to the tower. The chemical treatment utilizes 45 to 60 ppm alum, 75 ppm chlorine, and a corrosion inhibitor. The finished water quality is as follows ... 

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